Ive tried 5 cables with different length, all are cat5e and perfectly working with 1gbit with my other devices.

Month ago my odroid was working perfect with 1gbit with same cable and network setup but older image (dont know which version).Then I haved logged on my odroid for about 75 days and it was all time up and running. Yestureday then I decided to upgrade to new kernel when I saw, that eth0 was only connected with 100mbit.

I actually have seen this problem before. The issue is the cable. There were changes to ethernet drivers that "corrected" their negotiation behavior. Its not directly related to XU4 as I encountered the issue first on PC (its PHY related). To confirm if this is the problem, test with a known good Cat6 (not Cat5) cable.

crashoverride wrote:I actually have seen this problem before. The issue is the cable. There were changes to ethernet drivers that "corrected" their negotiation behavior. Its not directly related to XU4 as I encountered the issue first on PC (its PHY related). To confirm if this is the problem, test with a known good Cat6 (not Cat5) cable.

Same, I was hoping he had a CAT6 cable. I didn't have a lot of devices to test on at the time so I didn't realize it was the issue you describe.

My kernel version is 4.14.35.128, so i think the upgrade was successful.

Really strange...I was about to write, that it is finally connected with 1000mbit...And it really was connected few mins with 1000mbit and yellow led after cold start (odroid was off for about 2 days).

But now again its reconnected and back to 100mbit...

Maybe its a service wich is starting later and brings back the eth0 speed to 100mbit??

Thank you!This new file worked and I rebooted my odroid after installation.But unfortunately this kernel update didnt helped I also tried again to replug the cable and "ethtool -s eth0 speed 1000 duplex full autoneg off" -> no connectionAnd when Iam turning autoneg on again -> connected only with 100mbit

Kent446 wrote:Thank you!This new file worked and I rebooted my odroid after installation.But unfortunately this kernel update didnt helped I also tried again to replug the cable and "ethtool -s eth0 speed 1000 duplex full autoneg off" -> no connectionAnd when Iam turning autoneg on again -> connected only with 100mbit

So I think now it really looks like a hardware problem with the ethernet port of my XU4

But why then its connected some minutes with 1000mbit and then reconnecting with 100mbit?eth0 is connected internally with usb-bridge, isnt it?Maybe then the problem is a USB3.0 driver -> like falling back to USB 2.0 speed, causing eth0 also fall back to lower 100mbit speed?